2070: Mark & Molly live in London.

Long hours and hard work had severely sapped her sexual energy. But not so much, of course, that she and Mark hadn't been able to conceive a second time.

Mark had always been the faithful sort. He'd never cheated on anyone. Even when he was single and could afford to get high (before the government of National Unity became so ridiculously heavy-handed in enforcing the laws on drug possession), he'd never been keen on casual sex. He would never make love with a mate's girlfriend or wife. That just wouldn't be right. How would he like it if the same thing happened to him?

When their long working day was over, Mark and Molly made their separate ways to the tube stations through the rain-soaked streets of London. (Who said that Climate Change wouldn't bring even more rain to already soggy England?) As a devoted couple, they set their mobile phones to broadcast their whereabouts so that the other would know whether their partner was in the office or on the tube. This was a facility that had mostly gone out of fashion after it had been so spectacularly abused by the immigration police to locate people they wanted for what was euphemistically known as questioning. This had sometimes led to injury and even death as the police struggled to meet their monthly deportation totals.

Mark was reassured to see on his mobile phone that Molly was now walking along Chancery Lane to the tube station, while he was standing in the carriage of the Metropolitan Line train to Amersham. It was rather less comforting to know that due to yet another incident on the line, he would continue to be delayed in a stationary carriage between Baker Street and Finchley Road.

All around him were similarly frustrated passengers: many dripping wet from the heavy rain outside and all squeezed as tightly together as was possible. Most were also regarding their mobile phones, where they could send messages, watch television or just be entertained by music or films. Some passengers carried e-books, while a lucky few perched on the ridge of foam that passed for a carriage seat and were able to use their tablets.

Mark scanned his fellow passengers as best he could from the view he had past the elbows and umbrellas that poked near his face. They were less racially diverse than they would have been just over ten years before and dressed somewhat more shabbily. The age of cheap clothing, along with that for cheap food, was now just a distant dream. Nowadays people resorted more and more to patching up their worn-out socks and sweaters. There was even a good trade in supposedly indestructible fabrics that would never need repair. The one thing that remained cheap, of course, was electronic goods.

Along the side of the carriage was an array of plasma screens where once there would have been windows from which were broadcast soundless adverts for consumer goods, debt relief and film downloads. These were periodically interspersed by public information screens that informed Mark and the other passengers just how far the train was from the next stop and how long it would take to get there. The fact that these screens were stubbornly awaiting further information, as they had for the last ten sweaty humid minutes, provided no comfort at all.

Mark held his mobile phone up to within half a metre of his face and reviewed the news stories he could hear through the discreet ear-piece in his right ear.